Indian Journal of Science and Technology

Abstract

Objectives: In this paper a 1x4 optical beam splitter with a power splitting ratio of 80:20, based on 2D photonic crystal has been modeled for TE-polarized light. Methods: Designing of prototypes was done on the OptiFDTD software. Further, the simulations were performed and post-simulation the results were analyzed, this included the transmission spectra of the design which showed that the power was divided in a ratio of 80:20 that is 80 % and 20% of the transmitted signal. Also, the photonic band gaps were calculated using the Plane Wave Expansion (PWE) band solver. Findings: This prototype comprises of 2D Hexagonal lattice where the elliptical Si-rods are lined up in the air. The size of the wafer used for designing the prototype was taken to be 21µm*15µm.This particular design is a H-shaped splitter Finite Difference Time Domain (FDTD) and Plane Wave Expansion (PWE) methods are the mostly used mathematical analysis methods that are used for analyzing and calculating the band gap configuration and calculating the Photonic Band Gap of the photonic crystals. The Plane Wave Expansion method calculates the Eigen frequencies and dispersal characteristics of photonic crystals, with the help of Maxwell equations in frequency domain. The output power at output 1 and 3 was 80% and at the output 2 and 4 was calculated to be 20% of the transmitted signal. With the tolerance as 0.001, three band gaps were calculated and the values of their ban gaps were found to be 0.235179, 341851; 0.459574, 0.575928; 0.616383, 0.628378. Novelty/Improvement: This structure is designed in 1x4 dimensions, further the structure can be designed in various dimensions like 1x8, 1x16, 1x32 etc., depending on different applications. 

Keywords: Optical Splitter, Photonic Crystals, FDTD Simulation, PWE Band Solver